Environmental Management and Sustainability

Fifty years of environmental progress for United States dairy farms. Rotz CA, Beegle D, Bernard JK, Leytem A, Feyereisen G, Hagevoort R, Harrison J, Aksland G, Thoma G. J Dairy Sci. 2024 Jan 10:S0022-0302(24)00010-9.

  • Dairy farms in the United States (US) have changed in many ways over the past 50 years. Milk production efficiency has increased greatly with about 30% fewer cows producing about twice the amount of milk today. Other improvements include increases in crop yields, fuel efficiency of farm equipment and efficiency in producing most resources used on farms (electricity, fuel, fertilizer, etc.). These improvements have led to changes in the environmental impact of farms.
  • Through simulation of representative dairy farms in 1971 and 2020, changes in nutrient losses and farmgate life cycle assessments of greenhouse gas (GHG) emissions, fossil energy use, and blue (ground and surface) water use were determined for 6 regions and the US.
  • For all environmental metrics studied, intensities expressed per unit of fat and protein corrected milk produced were reduced, but the total impacts over all farms or milk produced increased for 5 of the 13 environmental metrics.
  • Reductions in the impacts of dairy farms in the eastern US were offset by large increases in western regions because of a major increase in cow numbers in the west. The national average intensity of GHG emissions decreased by 42%, which gave just a 14% increase in the total GHG emission of all dairy farms over the 50-yr period.
  • The intensity of fossil energy use decreased by 54% with the total for all farms decreasing 9%. Water use related to milk production decreased in intensity by 28%, but due to the large increase in dairy production in the dry western regions with greater dependence on irrigated feed crops, total blue water use increased 42%.
  • Major pathways of nitrogen loss included ammonia volatilization, leaching, and denitrification, where total ammonia emissions related to US dairy farms increased 29% while leaching losses decreased by 39% with little change in nitrous oxide emission. Simulated nitrogen and phosphorus runoff losses totaled for all dairy farms decreased 27 to 51% through more efficient fertilizer use, reduced tillage, and greater use of cover crops.
  • Emissions of methane and reactive non-methane volatile organic compounds increased 32% and 53%, respectively, due to greater use of long-term manure storage and silage stored in bunkers and piles.
  • Although much progress has been made in improving production efficiency, continued improvement with new strategies and technologies are needed to meet the demand for dairy products while mitigating total environmental impacts, particularly in view of projected climate variability.

Mitigation of gaseous emissions from dairy livestock: A farm-level method to examine the financial implications. Cantillon M, Hennessy T, Amon B, Dragoni F, O’Brien D. J Environ Manage. 2024 Jan 8;352:119904

  • Feeding the world’s population while minimizing the contribution of agriculture to climate change is one of the greatest challenges facing modern society. This challenge is particularly pronounced for dairy production where the carbon footprint of products and the mitigation costs are high, relative to other food stuffs.
  • This paper reviews a number of mitigation measures that may be adopted by dairy farmers to reduce greenhouse gas emissions from their farms.
  • A simulation model is developed to assess the cost-benefit of a range of mitigation measures. The model is applied to data from Ireland, a country with a large export-oriented dairy industry, for a range of farms including top, middle and bottom performing farms from a profitability perspective. The mitigation measures modelled included animal productivity, grass production and utilization, better reproductive performance, early compact calving, reduced crude protein, decreased fertilizer N, protected urea, white clover, slurry tank cover and low emission slurry spreading (LESS).
  • The results show that over half of the greenhouse gas abatement potential and most of the ammonia abatement potential were realized with cost-beneficial measures. Animal and feed-related measures that increased efficiency drove the abatement of GHG emissions. Low-emission slurry spreading was beneficial for the bottom and middle one-third of farms, while protected urea and reducing nitrogen use accounted for most of the ammonia abatement potential for the most profitable farms.
  • Results showed that combining mitigation measures resulted in a decrease of 23%, 19%, and 12% in GHG emissions below 2020 levels for the bottom, middle, and top performing dairy farms, respectively. The findings imply that top dairy farms, that are already managed efficiently and optimally, may struggle to achieve the national and international GHG reduction targets with existing technologies and practices.

Nutrient recovery from digestate: Pilot test experiments. Proskynitopoulou V, Zouboulis A, Panopoulos K, et al. J Environ Manage. 2024 Jan 26;353:120166.

  • A series of technologies have been employed in pilot-scale to process digestate, i.e. the byproduct remaining after the anaerobic digestion of agricultural and other wastes, with the aim of recovering nutrients and reducing the load of solids and organics from it, hence improving the quality of digestate for potential subsequent reuse.
  • In this case the digestate originated from a mixture of dairy and animal wastes and a small amount of agricultural wastes. It was processed by the application of several treatments, applied in series, i.e. microfiltration, ultrafiltration, reverse osmosis, selective electrodialysis and combined UV/ozonation.
  • The initially applied membrane filtration methods (micro- and ultra-filtration) removed most of the suspended solids and macromolecules with a combined efficiency of more than 80%, while the reverse osmosis (at the end) removed almost all the remaining solutes (85-100%), producing sufficiently clarified water, appropriate for potential reuse.
  • In the selective electrodialysis unit over 95% of ammonium and potassium were recovered from the feed, along with 55% of the phosphates. Of the latter, 75% was retrieved in the form of struvite.

Assessment of the performance of a symbiotic microalgal-bacterial granular sludge reactor for the removal of nitrogen and organic carbon from dairy wastewater. Bucci P, Marcos Montero EJ, García-Depraect O, Zaritzky N, Caravelli A, Muñoz R. Chemosphere. 2024 Jan 17;351:141250.

  • Cheese whey (CW) is a nutrient deficient dairy effluent, which requires external nutrient supplementation for aerobic treatment. CW, supplemented with ammonia, can be treated using aerobic granular sludge (AGS) in a sequencing batch reactor (SBR). AGS are aggregates of microbial origin that do not coagulate under reduced hydrodynamic shear and settle significantly faster than activated sludge flocs.
  • However, granular instability, slow granulation start-up, high energy consumption and CO2emission have been reported as the main limitations in bacterial AGS-SBR. Algal-bacterial granular systems have shown be an innovative alternative to improve these limitations. Unfortunately, algal-bacterial granular systems for the treatment of wastewaters with higher organic loads such as CW have been poorly studied.
  • In this study, an algal-bacterial granular system implemented in a SBR (SBRAB) for the aerobic treatment of ammonia-supplemented CW wastewaters was investigated and compared with a bacterial granular reactor (SBRB). Mass balances were used to estimate carbon and nitrogen (N) assimilation, nitrification and denitrification in both set-ups.
  • SBRBexhibited COD and ammonia removal of 100% and 94% respectively, high nitrification (89%) and simultaneous nitrification-denitrification (SND) of 23% leading to an inorganic N removal of 30%. The efficient algal-bacterial symbiosis in granular systems completely removed COD and ammonia (100%) present in the dairy wastewater.
  • SBRABmicroalgae growth could reduce about 20% of the CO2 emissions produced by bacterial oxidation of organic compounds according to estimates based on synthesis reactions of bacterial and algal biomass, in which the amount of assimilated N determined by mass balance was taken into account.
  • A lower nitrification (75%) and minor loss of N by denitrifying activity (<5% Ng, SND 2%) was also encountered in SBRABas a result of its higher biomass production, which could be used for the generation of value-added products such as biofertilizers and biostimulants.

Lactational performance, enteric methane emission, and nutrient utilization of dairy cows supplemented with botanicals. Martins LF, Cueva SF, Silvestre T, Stepanchenko N, Wasson DE, Wall E, Hristov AN. J Dairy Sci. 2024 Jan;107(1):242-257.

  • Botanicals, essential oils, phytonutrients, phytochemicals, and nutraceuticals are terms commonly used to define a diverse category of organic compounds derived from the secondary metabolism in plants with a broad spectrum of biological activities when fed to animals. Many of these plants, or associated compounds, are categorized as generally recognized as safe (GRAS) by the Food and Drug Administration of the United States (US Government, 2021), and they may be an alternative for improving dairy environmental sustainability, with greater appeal for consumers, when compared with synthetic feed additives.
  • Because nutrition is an effective way to increase dairy cow efficiency and decrease excretion of nutrients, adoption of feeding strategies and use of feed additives to mitigate the environmental impact of dairy production are being thoroughly investigated.
  • The objective of this study was to evaluate lactational performance, enteric gas emissions, ruminal fermentation, nutrient use efficiency, milk fatty acid profile, and energy and inflammatory markers in blood of peak-lactation dairy cows fed diets supplemented with Capsicum oleoresin or a combination of Capsicum oleoresin and clove oil.
  • A 10-wk randomized complete block design experiment was conducted with 18 primiparous and 30 multiparous Holstein cows. Cows were blocked based on parity, days in milk, and milk yield (MY), and randomly assigned to 1 of 3 treatments (16 cows/treatment):
    1. basal diet (CON);
    2. basal diet supplemented with 300 mg/cow per day of Capsicum oleoresin (CAP);
    3. basal diet supplemented with 300 mg/cow per day of a combination of Capsicum oleoresin and clove oil (CAPCO).
  • Premixes containing ground corn (CON), CAP, or CAPCO were mixed daily with the basal diet at 0.8% of dry matter intake (DMI).
  • Supplementation of the diet with CAP or CAPCO did not affect DMI, MY, milk components, and feed efficiency of the cows. Body weight (BW) was increased during the last 2 weeks of the experiment by CAP and CAPCO, compared with CON. The botanicals improved BW gain (0.85 and 0.66 kg/d for CAP and CAPCO, respectively, compared with -0.01 kg/d for CON) and CAP enhanced the efficiency of energy utilization, compared with CON (94.5% vs. 78.4%, respectively).
  • Daily CH4emission was not affected by treatments, but CH4 emission yield (per kg of DMI) and intensity (per kg of MY) were decreased by up to 11% by CAPCO supplementation, compared with CON and CAP. A treatment × parity interaction indicated that the CH4 mitigation effect was pronounced in primiparous but not in multiparous cows.
  • Ruminal molar proportion of propionate was decreased by botanicals, compared with CON. Concentrations of trans-10 C18:1 and total trans fatty acids in milk fat were decreased by CAP and tended to be decreased by CAPCO, compared with CON.
  • Blood concentrations of β-hydroxybutyrate, total fatty acids, and insulin were not affected by botanicals. Blood haptoglobin concentration was increased by CAP in multiparous but not in primiparous cows.
  • Lactational performance of peak-lactation dairy cows was not affected by the botanicals in this study, but they appeared to improve efficiency of energy utilization and partitioned energy toward BW gain.
  • In addition, CH4yield and intensity were decreased in primiparous cows fed CAPCO, suggesting a potential positive environmental effect of the combination of Capsicum oleoresin and clove oil supplementation.

Animal Health and Food Safety

CDRF-Funded Research: Farmers’ Perceptions on Implementing Automatic Milking Systems in Large USA Dairies: Decision-Making Process, Management Practices, Labor, and Herd Performance. Lage CFA, Marques TC, Bruno DR, Endres MI, Ferreira F, Pires APA, Leão K, de Lima FS. Animals (Basel). 2024 Jan 9;14(2):218.

  • Automatic Milking System (AMS) installations are increasing in the USA despite the higher investment cost than conventional systems. Surveys on AMSs conducted outside the USA focused on small-medium herds, specific regions, or aspects of AMS milking.
  • This study described farmers’ perceptions about the decision-making process of adopting an AMS in the USA’s large dairies (≥7 AMS boxes) regarding changes in technology, housing, management practices, labor, herd performance, and health.
  • After being contacted, 27 of 55 farmers from large AMS herds completed the survey. The main reasons for adopting an AMS were labor costs, cows’ welfare, and herd performance.
  • Most farms constructed new barns, used a free-flow traffic system, and changed their feed management. Increases in water and energy use were perceived by 42% and 62% of farmers, respectively. Farmers estimated decreases in labor costs of over 21%, and AMS employees worked 40-60 hours/week.
  • Milk production increases were reported by 58%, with 32% observing higher milk fat and protein content. Easier sick cow detection, better mastitis management, and improvements in pregnancy rates were reported.
  • Thus, farmers transitioning to AMSs perceived altered resource utilization, labor cost savings, and improvements in employee quality of life, animal welfare, and farm management. While 54% of respondents would recommend an AMS to other farms, 38% suggested considering additional aspects prior to adoption.

UC Davis-Led Research Effects of simplified group housing on behavior, growth performance and health of preweaned dairy calves on a California dairy. Abdelfattah EM, Aly SS, Lehenbauer TW, Karle BM. J Dairy Sci. 2024 Jan 19:S0022-0302(24)00017-1.

  • Most US dairy calves are raised in individual hutches (IH) for biocontainment purposes and to facilitate monitoring and handling of calves. However, individual hutches typically restrict calves’ activity and social interactions.
  • Previous studies showed that group housing (GH) is beneficial to calf welfare and is associated with social benefits. The adoption of group housing (GH) on dairies is hindered by several concerns, with the primary concern being the potential for increased transmission of diseases due to heightened calf-to-calf contact.
  • This study aimed to compare the behavior, health, and growth outcomes of calves housed in groups of 3 to individually housed (IH) calves during the preweaning period.
  • A total of 42 Holstein heifer calves on a commercial dairy in Northern California were enrolled in groups of 3 to different housing treatments; IH (n = 21) or GH (n = 21) between July and October 2020. Each treatment was composed of 7 groups of 3 calves each.
  • Calves in the GH treatment were housed in groups of 3 from 6 to 10 d until 70 days of age. Individual pens consisted of one polyethylene hutch with a 1.5 m x 1.2 m outside exercise area. Group pens were constructed by assembling 3 polyethylene hutches with a 1.5 m x 3.6 m outside exercise area of wire panel fencing.
  • Group-housed calves gained 0.64 ± 0.02 kg/day while IH calves gained 0.65 ± 0.02 kg/day. Similarly, there was no evidence for treatment differences in withers height gain in GH calves (0.22 ± 0.01cm/day) compared with IH calves (0.21 ± 0.01 cm/day). The cumulative incidence of BRD based on California scoring system in GH calves was 75 ± 9.68 compared with 66.66 ± 10.28% in IH calves.
  • Group-housed calves had a bovine respiratory disease hazard of 1.14 times that of IH calves. The cumulative incidence of diarrhea (fecal score 3) in GH calves was 100% in comparison to 95.20 ± 4.66% in IH calves. The mean proportion of scan observations of calves feeding on concentrates was significantly higher in GH compared with IH calves during the preweaning period.
  • The study results provide evidence that this simplified group housing system provides benefits of GH without detrimental short-term impacts during the preweaning period on calf growth and health.

UC Davis-Led Research Antimicrobial Susceptibility in Respiratory Pathogens and Farm and Animal Variables in Weaned California Dairy Heifers: Logistic Regression and Bayesian Network Analyses. Morgan Bustamante BL, Chigerwe M, Martínez-López B, Aly SS, McArthur G, ElAshmawy WR, Fritz H, Williams DR, Wenz J, Depenbrock S. Antibiotics (Basel). 2024 Jan 4;13(1):50.

  • Weaned dairy heifers are a relatively understudied production group. Bovine respiratory disease (BRD) is the most common cause of antimicrobial drug (AMD) use, morbidity, and mortality in this production group.
  • The study of antimicrobial resistance (AMR) is complicated because many variables that may affect AMR are related.
  • This study generates hypotheses regarding the farm- and animal-level variables (e.g., vaccination, lane cleaning, and AMD use practices) that may be associated with AMR in respiratory isolates from weaned dairy heifers.
  • A cross-sectional study was performed using survey data and respiratory isolates (Pasteurella multocidaMannheimia haemolytica, and Histophilus somni) collected from 341 weaned dairy heifers on six farms in California.
  • Logistic regression and Bayesian network analyses were used to evaluate the associations between farm- and animal-level variables with minimum inhibitory concentration (MIC) classification of respiratory isolates against 11 AMDs.
  • Farm-level variables associated with MIC classification of respiratory isolates included the number of source farms of a calf-rearing facility, whether the farm practiced onsite milking, the use of lagoon water for flush lane cleaning, and respiratory and pinkeye vaccination practices.
  • Animal-level variables associated with a MIC classification included whether the calf was BRD-score-positive and time since the last phenicol treatment.

Effect of Climatic Condition, Type of Trough and Water Cleanliness on Drinking Behavior in Dairy Cows. Burkhardt FK, Hayer JJ, Heinemann C, Steinhoff-Wagner J. Animals (Basel). 2024 Jan 13;14(2):257.

  • Increasing ambient temperatures lead to higher water intake and higher risks of microbial growth in cattle troughs.
  • This study aimed to analyze drinking water quality and dairy cows’ drinking behavior (n= 8081 drinking episodes) on a commercial farm with 135 and 144 lactating cows in two climatic conditions, considering trough type and cleanliness, respectively.
  • Daily video recording was conducted at two trough types (two open troughs, 70 L; two-valve troughs, variable volume of 5-15 L) in the first two hours after feeding (n= 60 days in total) under cold (December 2019-February 2020) and warm ambient temperatures (September 2021).
  • The trough cleaning scheme allowed cows to access either cleaned or uncleaned troughs in each system. Water quality was tested daily and analyzed at the beginning and end of the trials.
  • In warmer ambient temperatures, fewer and-at uncleaned troughs and open troughs-shorter drinking episodes were recorded, with longer but fewer water intake periods, longer drinking breaks, and fewer sips (p< 0.0001).
  • Considering the drinking episodes, respectively, water intake and drinking breaks in number and duration, the number of sips and the number of agonistic behaviors might optimize dairy cow water supply and hygiene management.

Zoonotic risks of pathogens from dairy cattle and their milk-borne transmission. Holzhauer M, Wennink GJ. J Dairy Res. 2024 Jan 8:1-7.

  • Dairy products are major sources of high-quality protein and bioavailable nutrients and dairy production contributes to local, regional and national-level economies. Consumption of raw milk and raw milk products does, however, carry a zoonotic risk, as does direct contact with cattle by farm husbandry staff and other employees.
  • This review will mainly focus on the latter, and deal with it from the standpoint of a well-developed dairy industry, using the example of the Netherlands.
  • With regard to dairy cattle, the main bacterial pathogens are SalmonellaListeria monocytogenesand Leptospira hardjo as well as Brucella abortus and Chlamydia abortus. The main viral pathogens associated with dairy are Rift Valley fever virus, rabies virus, cowpox virus and vaccinia virus. The main parasitological infections are Echinococcus granulosis, Cryptosporidium parvum and Giardia duodenalis, however, the last mentioned have mainly swimming pools as sources of human infection. Finally ectoparasites such as lice and mites and Trichophyton verrucosum may affect employees.
  • Some pathogens may cause health problems due to contamination. Bacterial pathogens of importance that may contaminate milk are Campylolobacter jejuni, Escherichia coli, Mycobacterium aviumparatuberculosisLeptospira hardjo and Salmonella typhimurium. Excretion of zoonotic viruses in milk is negligible in the Netherlands, and the endoparasite, Toxocara vitulorum is mainly found in suckling and fattening calves, whilst the risk in dairy cattle is limited. Excretion of transmissible spongiform encephalopathies (TSEs) or mycoses in milk are not expected and are, therefore, not of importance here.
  • Being aware of the risks and working according to hygiene standards can substantially limit zoonotic risks for employees. Additionally, diseased employees are advised to limit their contact with cattle and to indicate that they work with cattle when consulting a physician.
  • To prevent zoonotic risks through excretion of pathogens in milk, standard hygiene measures are necessary. Further, using only pasteurized milk for consumption and/or processing of milk can considerably limit the risks. If these measures are not possible, well-constructed monitoring can be followed. Monitoring programs already exist for pathogens such as for Salmonella spp., Leptospira hardjoand Mycobacterium avium paratuberculosis. For others, like Campylobacter jejuni and E. coli, programs are not available yet as far as we know.

Homogenization and thermal processing reduce the concentration of extracellular vesicles in bovine milk. Colella AP, Prakash A, Miklavcic JJ. Food Sci Nutr. 2023 Oct 8;12(1):131-140.

  • Extracellular vesicles (EVs) in bovine milk confer beneficial physiologic effects to consumers. Industrial processing treatments may affect the amount or bioactivity of EVs intrinsic to bovine milk.
  • Researchers investigated how the content and concentration of EVs were affected by homogenization and thermal processing of raw bovine milk.
  • Raw milk was processed by homogenization, low-temperature (LT) heat, or pasteurization [high-temperature short-time (HTST) and ultra-high-temperature (UHT)] in a pilot processing facility.
  • EVs were isolated from the raw and processed bovine milk using differential ultracentrifugation and quantified using a nanoparticle tracking analyzer. Bovine milk EVs were assessed for total miRNA and protein concentrations standardized to particle count.
  • There were 1.01 × 1010(±3.30 × 109) EV particles per ml of bovine milk. All industrial processing treatments caused >60% decrease in EV concentration compared to the raw bovine milk. Homogenization and heat treatments independently and additively reduced the content of EVs in bovine milk.
  • The averages of total miRNA/particle and total protein/particle concentrations were elevated threefold by low-temperature heat-processing treatment relative to HTST and UHT pasteurizations. The average diameter of EVs was reduced by 11%-16% by low temperature compared to raw milk (127 ± 13 nm).
  • Homogenization and pasteurization indiscriminately reduce the EV concentration of bovine milk. Smaller EVs with higher protein content resist degradation when processing bovine milk at sub-pasteurization temperature. This new foundational knowledge may contribute to food product development on the preservation of EVs in processed dairy products, including bovine milk-based infant formulas that some newborns are dependent on for adequate growth and development.

Human Health and Nutrition

The protective association of dairy intake and the adverse impact of iron on gestational diabetes risk. Pouladi F, Nozari E, Hosseinzadeh F, Hashemi S. Int J Vitam Nutr Res. 2024 Jan 17.

  • Gestational diabetes (GDM) is a pregnancy-related glucose intolerance with significant implications for maternal and fetal health. Calcium is essential for insulin secretion and metabolism, while iron intake may also impact GDM.
  • This case-control study was conducted to investigate the relationship between calcium and iron intake with the risk of GDM.
  • A 168-Item food-frequency-questionnaire was used to collect dietary calcium and iron intake from 24-40 weeks of gestation. The impact of total iron, red, processed/unprocessed meat consumption, calcium, and dairy intake on GDM were investigated.
  • A total of 229 GDM and 205 non-GDM women (18-45 years) participated. GDM group had higher pre-pregnancy weight, weight gain, and pre-pregnancy BMI.
  • Across all models, GDM risk significantly increased in the third and fourth quartiles of iron intake. The fourth quartile had an Odds Ratio (OR) of 2.68 compared to the reference. Heme-iron consumption in the fourth quartiles increased GDM risk.
  • In the second calcium intake model, ORs for the second, third, and fourth quartiles were 0.51, 0.43, and 0.35, respectively, reducing GDM risk by 50-65% compared to the first quartile. Dairy consumption in all quartiles of the first and second models was associated with lower GDM risk.
  • In conclusion, consumption of heme-iron through red and processed meat associated with an increased chance of developing GDM. Dairy intake reduces the chances of developing GDM in pregnant women.

Dairy product consumption, eating habits, sedentary behavior and physical activity association with bone mineral density among adolescent boys: a cross-sectional observational study. Kopiczko A, Czapla M, Juárez-Vela R, Ross C, Uchmanowicz B. BMC Pediatr. 2024 Jan 17;24(1):53.

  • During childhood and adolescence, skeletal microarchitecture and bone mineral density (BMD) undergo significant changes. Peak bone mass is built and its level significantly affects the condition of bones in later years of life. Understanding the modifiable factors that improve bone parameters at an early age is necessary to early prevent osteoporosis.
  • To identify these modifiable factors researchers analyzed the relationship between dairy product consumption, eating habits, sedentary behavior, and level of physical activity with BMD in 115 young boys (14-17 years).
  • Dairy product consumption and eating habits were assessed by means of a dietary interview. Sedentary behavior and physical activity was assessed in a face-to-face interview conducted using the International Physical Activity Questionnaire.
  • Relationships between BMD, bone mineral content (BMC) in the distal and proximal part of the forearm and PA, sit time and eating parameters were evaluated using the multiple forward stepwise regression.
  • The strongest relationships with BMD in distal part of forearm were found for moderate plus vigorous activity, sit time, and intake of dairy products, intake of calcium, protein, vitamin D, phosphorus from diet.
  • In conclusion, high physical activity and optimal eating habits especially adequate intake of important dietary components for bone health such as calcium, protein, vitamin D and phosphorus affect the mineralization of forearm bones.

Effect of high in comparison to low dairy intake intervention on markers of bone and cartilage remodeling and phosphate metabolism in healthy adults with overweight. van der Vaart A, Eelderink C, van den Heuvel EGHM, Feitsma AL, van Dijk PR, de Borst MH, Bakker SJL. Eur J Nutr. 2024 Jan 6.

  • In the ageing population, issues with bone and joint health are highly prevalent. Both beneficial and potential risks of dairy products on bone and joint health are reported in epidemiological studies. Furthermore, the phosphorus load from dairy could potentially lead to unfavorable changes in phosphorus metabolism.
  • The objective of this study was to investigate the effect of dairy intake on markers of bone and joint metabolism and P metabolism in an intervention study with high and low dairy intake.
  • In a post hoc analysis of a randomized cross-over trial with overweight adults, the effect of a standardized high dairy intake (5-6 dairy portions per day) versus low dairy intake (≤ 1 dairy portion/day) for 6 weeks on markers of bone and joint health was assessed. Markers indicative for cartilage breakdown, including urinary CTX-II, serum COMP and 4-hydroxyproline, and markers indicative for bone remodeling, such as serum CTX-I, PTH, 25(OH)D, osteocalcin, P1NP and FGF23, were investigated using linear mixed models. Furthermore, changes in phosphorus metabolism, including the main phosphate-regulating hormone FGF23 were explored.
  • The study was completed by 46 adults (57% female, age 59 ± 4 years, BMI 28 ± 2 kg/m2). Following the high dairy diet, markers such as urinary CTX-II excretion, COMP, 25(OH)D, PTH and CTX-I were significantly lower, as compared to the low dairy diet. Concurrently, phosphorus intake was higher at high dairy diet than at low diet, but plasma levels were not. FGF23 levels tended to be higher with high dairy intake than low dairy intake.
  • In conclusion, a high dairy diet as compared to a low dairy diet, reduced markers that are indicative for joint and bone resorption and bone turnover. No changes in phosphorus metabolism were observed.

The association of milk products with rheumatoid arthritis: A cross-sectional study from NHANES. Chen W, Jiang D, Liu K, Lyu L, Chen Y, Sun X, Mao Y, Ye D. Joint Bone Spine. 2024 Jan;91(1):105646.

  • Milk products are a major part of the western diet, but the role of their effect in rheumatoid arthritis (RA) is controversial.
  • The objective of this study was to explore the relationship between milk products and RA in the United States (US) population.
  • In the cross-sectional study, a total of 12,813 participants aged 20 years or older were selected from the National Health and Nutrition Examination Survey (NHANES). Consumption of milk products was collected by personal interview, and RA status was obtained by self-reported questionnaires. The association between milk products and RA was estimated by using the weighted logistic regression model.
  • The researchers found an inverse association of once a day or more milk products intake with self-reported RA prevalence (odds ratio [OR]: 0.68). A linear trend between consumption of milk products and the prevalence of RA was also observed.
  • In subgroup analysis, protective effects of milk products on RA were more pronounced in several groups (i.e., Mexican Americans, highly educated and drinking individuals, etc.). However, no interaction effect of stratification variables and the frequency of milk products intake with RA was detected.
  • This study  indicated that high consumption of milk products was associated with a reduced possibility of developing RA within the US population. Further investigations are warranted to validate the causal association and the underlying mechanism.

Metabolic effects of milk fatty acids: A literature review. Muñoz-Alvarez KY, Gutiérrez-Aguilar R, Frigolet ME. Nutr Bull. 2024 Jan 16.

  • Milk and dairy products are known to have a significant role in human development and tissue maintenance due to their high nutritional value. With the higher incidence of obesity and metabolic diseases, nutrition and public health authorities have recommended the intake of fat-free or low-fat dairy due to the saturated fatty acid content of whole-fat products and their effect on serum cholesterol levels. However, recent studies have questioned the association between milk fat consumption and cardiometabolic risk.
  • This literature review aims to compile the scientific evidence of the metabolic effects of milk fatty acids in clinical and basic research studies, as well as their relationship with metabolic disorders and gut microbiota composition.
  • Research shows that various milk fatty acids exert effects on metabolic alterations (obesity, type 2 diabetes and cardiovascular diseases) by modifying glucose homeostasis, inflammation and lipid profile-related factors. Additionally, recent studies have associated the consumption of milk fatty acids with the production of metabolites and the promotion of healthy gut microbiota.
  • From mainly observational studies, evidence suggests that milk and dairy fatty acids are not directly linked to cardiometabolic risk, but further controlled research is necessary to clarify such findings and to assess whether dietary recommendations to choose low-fat dairy foods are necessary for the population for the prevention of obesity and cardiometabolic disease.

Milk fat globule membrane modulates inflammatory pathways in human monocytes: A crossover human intervention study. Deng L, Michielsen CCJR, Afman LA, et al. Clin Nutr. 2024 Jan;43(1):232-245.

  • Intake of high-fat foods raises postprandial plasma triglycerides and inflammatory markers, which may depend on the type of fat ingested. Dairy products are commonly consumed, but not much is known about the impact of milk fat and the milk fat globule membrane on postprandial inflammation.
  • Here, researchers aimed to study the effect of milk fat with and without milk fat globule membrane and a vegetable fat blend on post-prandial inflammation, with a focus on blood monocyte gene expression.
  • The researchers performed a randomized, double-blind cross-over trial in 37 middle-aged healthy male and female volunteers (BMI 22-27 kg/m2). The participants consumed a meal shake containing 95.5 g of fat consisting of either a vegetable fat blend (VEGE), anhydrous milk fat (AMF, without milk fat globule membrane), or cream (CREAM, containing milk fat globule membrane).
  • Consumption of all three shakes significantly decreased the percentage of classical monocytes and increased the percentages of intermediate monocytes and non-classical monocytes. No differences in these measures were observed between shakes. 787 genes were differentially regulated postprandially between the three shakes. 89 genes were differentially regulated postprandially between AMF and VEGE, 373 genes between AMF and CREAM, and 667 genes between VEGE and CREAM, indicating that the effect of CREAM on monocyte gene expression was distinct from AMF and VEGE.
  • Pathway analyses showed that VEGE significantly increased the expression of genes involved in inflammatory pathways, whereas this was less pronounced after AMF and not observed after CREAM.
  • In addition, CREAM significantly down-regulated the expression of genes involved in energy metabolism-related pathways, such as glycolysis, TCA cycle, and oxidative phosphorylation, as well as HIF-1 signaling.
  • In conclusion, compared to the consumption of an anhydrous milk fat without milk fat globule membrane and a vegetable fat blend, the consumption of cream with milk fat globule membrane downregulated inflammatory pathways in blood monocytes, thus suggesting a potential inflammation inhibitory effect of milk fat globule membrane.

Variant of the lactase LCT gene explains association between milk intake and incident type 2 diabetes. Luo K, Chen GC, Qi Q, et al. Nat Metab. 2024 Jan;6(1):169-186.

  • Cow’s milk is frequently included in the human diet, but the relationship between milk intake and type 2 diabetes (T2D) remains controversial.
  • Here, using data from the Hispanic Community Health Study/Study of Latinos, researchers show that in both sexes, higher milk intake is associated with lower risk of T2D in lactase non-persistent (LNP) individuals (determined by a variant of the lactase LCT gene, single nucleotide polymorphism rs4988235 ) but not in lactase persistent individuals. Researchers validate this finding in the UK Biobank.
  • Further analyses reveal that among LNP individuals, higher milk intake is associated with alterations in gut microbiota (for example, enriched Bifidobacterium and reduced Prevotella) and circulating metabolites (for example, increased indolepropionate and reduced branched-chain amino acid metabolites). Many of these metabolites are related to the identified milk-associated bacteria and partially mediate the association between milk intake and T2D in LNP individuals.
  • This study demonstrates a protective association between milk intake and T2D among LNP individuals and a potential involvement of gut microbiota and blood metabolites in this association.

Innovation, Economics, and Dairy Alternatives

Right on the money? U.S. dairy farmers’ varied understanding of consumer preferences and attitudes towards animal health, welfare and biotechnology. Ufer DJ, Ortega DL. J Dairy Res. 2024 Jan 8:1-4.

  • Farmers play a critical role in supplying food markets, and their responsiveness to the market is dependent on an accurate perception of what consumers demand. While market signals exist to help this process along, a farmer’s ability to anticipate trends based on consumer preferences can be vital to their operation’s survival and profitability.
  • This article investigates how well U.S. dairy farmers understand the voting behavior and willingness to pay of consumers for products with production traits relevant to animal health, welfare and biotechnology.
  • S. dairy farmer perceptions of consumer likelihood to pay a premium or propensity to support regulations were collected in a March 2020 mail survey. Farmers in six states were surveyed (California, Minnesota, Michigan, Wisconsin, New Mexico, and Vermont), representing major U.S. dairying regions.
  • The sample consists of 399 active dairy farmers, with herd sizes ranging from less than 10 milking head of cows up to 12 000 head. The average age was 54 with an average farming tenure of 34 years. Approximately 11% of the sample were female and 12% had organic operations.
  • Comparing survey data with the literature shows that U.S. dairy farmers correctly assess consumer attitudes and behavior over animal welfare practices like pain-controlled dehorning but could improve knowledge of attitudes towards antibiotic use and novel biotechnologies like gene editing.
  • In conclusion, this analysis indicates that U.S. farmers have a fair understanding of the consumer’s mind with respect to important issues in livestock production, but there is room for improvement. This improvement could help farmers, as well as the cooperatives so many U.S. dairy farmers are members of, to become more aware of and better able to tap into growing markets for alternative production practices which meet consumer demands.
  • Similarly, an increased effort on the part of farmers to understand the consumer could be essential to identifying communication priorities and strategies to help shape a more positive consumer understanding of conventional production practices and reduce producer risk at the ballot box.

Dairy nutrition educational messages help increase dairy product knowledge, purchasing, and consumption. Myers J, Schweiger D, Clark S. JDS Commun. 2023 Oct 6;5(1):13-17.

  • The Dietary Guidelines for Americans, 2020–2025, recommends that a healthy adult who consumes 2,000 calories should include 3 cups equivalent of dairy or soy alternatives per day; however, males and females aged 19 to 59 years, on average, are consuming about 2 and <1.5 cups of dairy a day, respectively. Inadequate dairy consumption has negative nutritional consequences.
  • To combat the decline in milk consumption and to increase the consumption of dairy foods, groups such as Dairy Management Inc. have developed educational materials in a variety of formats (e.g., infographics, advertisements) and delivery platforms (e.g., social media influencers, print).
  • The objectives of this research were to educate those who consume an inadequate amount of dairy (less than 3 servings of dairy per day) about various topics related to dairy nutrition, test retention of information, and motivate purchasing and consumption of dairy products.
  • Twenty-four nominal focus group (NFG) sessions were conducted. The NFG were randomly assigned into control or treatment groups. The control only received a nutrition facts panel (NFP) label lesson. Treatment groups received the NFP label lesson, plus one of 3 different educational messages (EM; lactose maldigestion, 9 essential nutrients, and prebiotics and probiotics). Identical scripts were followed, except for the EM and infographics.
  • Participants completed surveys at the beginning (pre-survey) and end (post-survey) of the NFG, and 1 month later (follow-up). A total of 195 participants completed the NFG and pre- and post-surveys; 185 of those completed the follow-up survey.
  • Participants learned about dairy nutrition topics (validated by correct responses in survey questions) and increased their consumption and purchasing of cheese, ice cream, milk, and yogurt by at least 20% after participating in an NFG.
  • Consumption did not increase enough for those who consume an inadequate amount of dairy to meet the recommended 21 servings of dairy per week. Adjustments to the EM and infographics may improve learning, knowledge retention, and more meaningfully increase dairy purchasing and consumption.

Database of Food Fraud Records: Summary of Data from 1980-2022. Everstine KD, Chin HB, Lopes FA, Moore JC. J Food Prot. 2024 Jan 19:100227.

  • Food fraud prevention and detection remains a challenging problem, despite recent developments in regulatory and auditing requirements. In 2012, the United States Pharmacopeial Convention created a database of food ingredient fraud.
  • The objective of this research was to report on updates made to the database structure and to provide an updated analysis of food fraud records. The re-structured database was relational and included four tables: ingredients, adulterants, adulteration records, and references.
  • Four adulteration record types were created to capture the variety of information that can be found in public food fraud reports. Information was searched and extracted from the peer-reviewed scientific literature, media publications, regulatory reports, judicial records, trade association reports, and other public sources covering 1980-present.
  • The ingredients with the highest number of incident and inference records included fluid cow’s milk, extra virgin olive oil, honey, beef, and chili powder.
  • The ingredient groups with the highest number of incident and inference records included Dairy Ingredients, Seafood Products, Meat and Poultry Products, Herbs, Spices, and Seasonings, Milk and Cream, and Alcoholic Beverages.
  • This database was created to serve as a standardized source of information about publicly documented occurrences of food fraud and other information relevant to fraud risk to support food fraud vulnerability assessments, mitigation plans, and food safety plans. This data supports the contention that food fraud presents a public health risk that should continue to be addressed by food safety systems worldwide.

Cow’s Milk: A Benefit for Human Health? Omics Tools and Precision Nutrition for Lactose Management. Pratelli G, Tamburini B, Badami GD, Lo Pizzo M, De Blasio A, Carlisi D, Di Liberto D. Nutrients. 2024 Jan 22;16(2):320.

  • Cow’s milk (CM) is a healthy food consumed worldwide by individuals of all ages. Unfortunately, “lactase-deficient” individuals cannot digest milk’s main carbohydrate, lactose, depriving themselves of highly beneficial milk proteins like casein, lactoalbumin, and lactoglobulin due to lactose intolerance (LI), while other individuals develop allergies specifically against these proteins (CMPA).
  • The management of these conditions differs, and an inappropriate diagnosis or treatment may have significant implications for the patients, especially if they are infants or very young children, resulting in unnecessary dietary restrictions or avoidable adverse reactions.
  • Omics technologies play a pivotal role in elucidating the intricate interactions between nutrients and the human body, spanning from genetic factors to the microbiota profile and metabolites.
  • This comprehensive approach enables the precise delineation and identification of distinct cohorts of individuals with specific dietary requirements, so that tailored nutrition strategies can be developed. This is what is called personalized nutrition or precision nutrition (PN), the area of nutrition that focuses on the effects of nutrients on the genome, proteome, and metabolome, promoting well-being and health, preventing diseases, reducing chronic disease incidence, and increasing life expectancy.
  • Here, researchers report the opinion of the scientific community proposing to replace the “one size fits all” approach with tailor-made nutrition programs, designed by integrating nutrigenomic data together with clinical parameters and microbiota profiles, taking into account the individual lactose tolerance threshold and needs in terms of specific nutrients intake.
  • This customized approach could help LI patients to improve their quality of life, overcoming depression or anxiety often resulting from the individual perception of this condition as different from a normal state.

Plant-Based Milk Consumption and Growth in Children 1-10 Years of Age. Soczynska I, da Costa BR, O’Connor DL, Jenkins DJ, Birken CS, Keown-Stoneman CD, Maguire JL. J Nutr. 2024 Jan 12:S0022-3166(23)72836-8.

  • The effects of plant-based milk consumption on the growth of children are unclear.
  • Therefore, researchers aimed to evaluate the relationship between plant-based milk consumption and BMI in childhood. Secondary objectives were to examine the association with height and whether these relationships are mediated by dairy milk intake and modified by age or type of plant-based milk.
  • A prospective cohort study was conducted in healthy children aged 1-10 y through TARGet Kids!, a primary care research network in Toronto, Canada. Linear mixed-effect modeling and logistic generalized estimating equations were used to evaluate the association between plant-based milk consumption (number of 250 mL cups/d) and BMI.
  • Among 7195 children (mean age: 3.1 y; 52.3% male), higher plant-based consumption was associated with lower BMI and height. No association was found with BMI categories. Lower dairy milk intake partially mediated these relationships.
  • A child aged 5 years who consumed 3 cups of plant-based milk compared with 3 cups of dairy milk had a lower weight of 0.5 kg and lower height of 0.8 cm. Associations did not change over time and were similar for children who consumed soy milk compared with other plant-based milks.
  • In conclusion,plant-based milk consumption was associated with lower BMI and height, but both were within the normal range on average. Future longitudinal studies are needed to determine whether these associations persist over time.

Bioaccessibility and Digestibility of Proteins in Plant-Based Drinks and Cow’s Milk: Antioxidant Potential of the Bioaccessible Fraction. Khamzaeva N, Kunz C, Schamann A, Pferdmenges L, Briviba K. J Agric Food Chem. 2024 Jan 18.

  • During the last years, a strong increase in the sales volume and consumption of plant-based drinks was observed, which were partly used as an alternative to cow’s milk.
  • As milk is a relevant protein source in many countries, researchers have investigated the protein bioaccessibility and digestibility of soy, almond, and oat drinks in comparison to milk using the tiny-TIMsg gastrointestinal model.
  • The relative protein digestibility of all products was between 81% (soy drink) and 90% (milk). The digestible indispensable amino acid score (DIAAS) in vitro method was used to estimate the protein nutritional quality.
  • The highest DIAAS values were obtained for milk in tryptophan (117%) and soy drink in sulfur containing amino acids (100%). Oat drink was limited in lysine (73%), almond drink in lysine (34%) and the sulfur containing amino acids (56%).
  • Additionally, the antioxidant activity of the bioaccessible fractions was analyzed using Trolox equivalent antioxidative capacity and oxygen radical absorbance capacity assays, revealing a higher antioxidative potential of milk and soy drink compared to oat and almond drink.